"There is no doubt that we can be thankful that there weren't some more significant injuries considering the place where the explosion occurred and the extent of the debris," he said.

The fire service and police are reviewing CCTV footage of the explosion.

The service's Rod Sherrin says the investigation is focussing on the ute.

"What we can tell is that the driver left the ute to come and pay for his purchase of fuel and he turned around to lock his vehicle with his central locking and when he pressed the button that's when the explosion occurred," he said.

Witness Gabrielle Synnott was next door and said she heard the explosion.

"There was about five vehicles in the bay at the time - they've all lost their windows," she said.